Honing machine



Sept. 5, 1939.

J. E. e. KLINE 2,171,799

HONING MACHINE Filed Dec. 10, 1956 8 Sheets-Sheet 1 fly. 1.

INVENTOR. JOHN E.G. K LINE 7 ATTORNEY.

J. E. G. KLINE HONING MACHINE Sept. 5, 1939.

Filed Dec. 10, 1956 8 Sheets-Sheet 2 fig. 2.

OOOOOO Fei-cktkflititsl INVENTOR.

JOHN E.G. KLJNE BY Wm ATTORNEY.

p 5, 1939 J. E. G. KLINE 2,171,799

HONING MACHINE Filed Dec. 10, 1936 8' Sheets-Sheet 3 A l VIIIIA III JOO

INVENTOR. J N L6. KLINE.

f MWM ATTORNEY.

Sept. 5, 1939.

J. E. G. KLINE HONING MACHINE Filed Dec. 10, 1936 8 Sheets-Sheet 4 NDN INVENTQR. IJOHN E..G. KLINE MUM ATTORNEY.-

J. E. G. KLINE HONING MACHINE Sept. 5, 1939.

Filed Dec. 10, 1936 8 Sheets-Sheet 5 INVENTOR. dOHN LG. KLINE.

ATTORNEY.

p 1 J. E. G. KLINE v 2,171,799

HQNING MACHINE Filed Dec. 10, 1936 8 Sheets-Sheet 6 INVENTOR. IJOHN v1.6. KLINE'.

ATTORNEY.

Sept. 5, 1939.

J. E. G. KLINE HONING MACHINE Filed Dec. 10, 1936 8 Sheets-Sheet INVENTOR. \JOHN 2.6. KLINE:

ATTORNEY.

p 1939- I J. E. G. KLINE 2,171,799

HON'ING MACHINE Filed Dec. 10, 1936 8 Sheets-Sheet 8 i 00 f A ll I wa m @gsg W I Am g w. S \IK /IQ INVENTOR. JOHN E.. 6. KLINE.

BY MW ATTORNEY.

Patented Sept. 5, 1939 UNITED STATES PATENT OFFICE HONING MACHINE Application December 10, 1936, Serial No. 115,225

16 Claims. (CI. 51-34) The present invention relates to a machine for honing cylinders to a true contour and is specifically directed to a manner by which a rotating spindle carrying the honing tool is reciprocated in the bore of a cylinder of an internal'combustion engine or the like including means for controlling the movement of the spindle.

In carrying out a cylinder grinding operation the honing tool is inserted in the bore to be finished and the same is rotated and reciprocated to abrade the cylinder wall. During the honing or finishing operation the tool must be longitudinally moved while rotated within such limits as will prevent the tool from passing out of the ends of the bore since the expanded abrasive stones will not permit the tool to reenter the cylinder. It is also necessary to move the tool back and forth lengthwise of the cylinder to points adjacent the ends thereof so as to prevent excessive abrading along the central portion of the bore as compared to the grinding at the ends. In other words barrel shaping of the cylinder surface must be avoided. The reciprocation of the tool must therefore be positive and the length of the recurring stroke must be the same for each reversal irrespective of the reciprocating speed to provide a perfect cylindrical finish to a given cylinder.

It is therefore an object of the invention to provide a machine adaptable to such a honing operation in which one or more honing tools are operatively supported by a reciprocatory spindle having a driving mechanism operating to effect rotation of the tool or tools simultaneously with the proper reciprocatory movement.

In certain types of honing machines of the prior art the spindle has been reciprocated by means of a hydraulic mechanism to provide smooth reversal of the spindle which cannot be obtained conveniently by the use of wholly mechanical mechanisms. The longitudinal movement of the spindle by means of a hydraulically actuated piston directly connected to reciprocate the spindle through a stroke corresponding to the movement of the piston has the undesirable characteristic of requiring an intricate control mechanism to reverse the stroke at a proper point for spindle structure. I a v Such a machine is impractical vi'or use in driving ahoning tool in certaintypes of cylinders such as the closed end type employed in many airplane engines. That is to say, the bore of such a cylinder must be abraded lengthwise thereof to a point immediately adjacent the closed end and the point of reversal must therefore be definite andpositive. The tendency of the hydraulic operated machines known to the art to overrun or underrun render them unsatisfactory for finishing such types of cylinders.

A further object of the invention is therefore to provide a mechanism for eflecting reciprocatory movement of the honing tool with means by which the length of the stroke may be adjusted for operation in a given cylinder whereby the character of the reciprocating mechanism will cause the tool to be positively moved within definite limits.

Another object of the invention is to provide a mechanism wherein the honing tool is moved longitudinally of the cylinder in such a manner that each back and forth movement is exactly the same and to supplement such a mechanism with simple means for withdrawing the tool from the cylinder at the end of the honing operation.

Other and further features and objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawings and the following description.

wherein an exemplary embodiment of the inven tion is disclosed. v

In the drawings:

Fig. 1 is a perspective view of the machine showing the front and left sides.

Fig. 2 is a front elevation of the machine with part of the casing broken away.

Fig. 3 is an elevation in part section of the machine fromthe right side. I

Fig. 4 is a section on line IVIV of- Fig. 3.

Fig. 5 is a view of the reciprocating mechanism mounting assembly with the reciprocating cylin der and associated parts in section.

Fig. 6 is a detail of the liftout cylinder assembly.

Fig. '7 isa part section through the top of the machine showing details of the speed changing mechanism. I.

Fig. 8 is a diagrammatic view of one form of control mechanism showing valves 5; 8 and H assembly looking from the front of the machine. Fig. 11 is. a hydraulic circuit diagram of the 2 machine.

Fig. .12 -is a diagrammatic, view-showingthe positions of the various valves when the reciprocating cylinder is traveling upwardly and the spindle is traveling downwardly.

Fig. 13 is a diagrammatic view, similar to Fig. 12, except that the valvesare shown as they are when the reciprocating cylinder is traveling downwardly and the spindle is traveling upwardly. I

Fig. 14 is a diagrammatic view which illustrates the positions of the valves 6, 1 and 9 when the lever F has been thrown to stop the machine.

Referring specifically to Figs. 1, 2 and 3, the machine comprises a base I on which is mounted an upright body portion referred to generally as. 0|.

The lower part of the body portion houses an electric motor 102 which constitutes the prime mover of the machine (see Figure 3.) This motor drives a pump I03 (see Fig. 4) which supplies fluid pressure to the various hydraulic cylinders and valves, and also furnishes rotative power to the honing tool I04 through the intermediary of shaft I15, gear train I16, pulleys I11 and I11; clutch G, gear trains I18 and I19 and splined shaft H0. Hand wheel 5 is for the purpose of varying the rotation speed of the hone. The speed changing mechanism will be described later on in this specification.

The honing tool 104 is of the type well known in the art and consists essentially of a head I05, which has a number of radial slots in which abrasive stones are mounted. These stones are adapted to be adjustable radially of the head so that the head can be inserted into the bore of the workpiece and the stones expanded to engage the cylinder wall.

The motor I02 also drives, through the belt 99, a coolant pump which supplies coolant from the sump 98 to the bore of the workpiece 91.

4 The workpiece 91 is supported on a table 96 which is vertically adjustable by means of Jackscrew 95.

- As stated above, the honing operation requires that the tool be reciprocated in the bore as well as rotated, and the mechanism for reciprocating the tool comprises essentially a normally stationary cylinder C, hereinafter referred to as the liftout cylinder, a reciprocating cylinder D, and a gear sector member B.

Gear sector member B is provided with two sets of gear teeth I05 and I01 which are adapted to mesh respectively with the rack I09 on the liftout cylinder C and rack I09 on the spindle. A.

Gear sector member B is also provided with a pivot pin H0 which is mounted in a crosshead H i for sliding movement under the influence of the connecting rod K. The crosshead III is mounted in the body wall as shown in Fig. 3.

The connecting rod K is connected at its opposite end with the crank E which is in turn fixed to the shaft Ill. Shaft I I4 is journaled in the rear of the plate 300 (see Figs. 2 and 9) and has the pinion H5 keyed thereon. The teeth of" pinion |l5 mesh with rack 6 which is on the outside of the reciprocating cylinder D.

Crank E is adjustable as to throw'and consists of (see Fig. 10) a channel shaped member H3 fixedly mounted on the outer end of shaft 4, and a slidable member H3, which carries the crankpin 11 on which the lower end of the connecting rod K is journaled. An adjusting screw 10 is mounted, by means of a suitable thrust bearing 12, in the lower end of the channel shaped member H3. It will be apparent from Fig. 10 that the crank throw my be a jlut i by applying a wrenchto the head on the bottom end of screw 10. v

The details of the reciprocating cylinder D are shown in Fig. 5. 4

Cylinder D and its associated mechanism, are mounted on a plate 300 (Figs. 2, 5, 9 and 10) which is removable from the housing by loosening bolts 301.

Cylinder D is mounted for sliding movement on the piston 302 and piston rod 303, the latter of which is fixed at each end to the supports 304 and 305 of plate 300.

The piston rod 303 has longitudinal passageways 306 in each end thereof. These passageways extend into the piston rod to points closely adjacent each other, as shown by Fig. 5, and each communicates with the interior of the cylinder by means of ports 301 and 308 one of which is provided with a ball check 309. Cylinder head 3i0 is provided with a cylindrical extension 3l0' which extends a considerable distance into the bore. This cylindrical extension 3l0' cooperates with ports 301 and 309 to effectively cushion the shock when the cylinder D reverses its direction of movement.

As is obvious from the drawings, when the cylinder D approaches the end of its stroke in the downward direction, passageways 301 (of which there are four) are cut off by the cylindrical extension 310' and the oil which was being exhausted through passage 309 is cut oil before the piston 302 comes in contact with the end of the extension 3| 0'. Because the ball check 309 is closed by the spring, a quantity of oil is trapped between the piston and the extension and thus forms a cushion.

On the other hand, when the flow of oil is reversed by means of pilot valve 1 and valve 6, the passageway 301 is still closed by the extension 310' and the oil pressure can reach the expansion chamber through the passage 308 only. 1

Due to the fact that this passage is restricted by the ,spring biased ball 309, the flow of oil into the expansion chamber is retarded so that a gradual reverse of the cylinder is obtained. As soon as the cylinder moves upwardly far enough so that the passageway 301 is uncovered, then the movement is accelerated to its full speed until the end of the stroke is reached in the other direction. It is of course to be understood that the construction of cylinder D is identical at both ends.

Liftout cylinder C will now be described in detail. This cylinder is used for inserting the honing tool into the bore of the Workplace and for withdrawing it therefrom at the end of the honing operation. During the time which the workpiece is being honed cylinder C occupies a stationary position at the top of its stroke.

Referring to Fig. 6, liftout cylinder Ccomprises an outside casing 200 on which is mounted a rack I00 which has teeth adapted to mesh with teeth I06 on the gear sector member B. Piston rod 202 is mounted at its upper end on a projecting shelf 203 which projects from the rear side of the machine casing (Figs. 3 and 6), and at its lower end on a similar projecting shelf 200.

Journaled on the rod 202 at its lower end is an elongated adjusting nut 205. This adjusting nut has threads 206 on its outer side which engage complementary threads 201 on member 2. Thus it can be seen that by screwing the member 20! upwardly or downwardly the downmost position of the cylinder C can be accurately fixed.

Piston 201 is fixed on the rod 202 which has a hollow bore 208. This bore forms a passageway which communicates with the expansion chamber 209 through ports H0. The construction of the upper end of the cylinder C is identical with this.

Thus it can be readily seen that fluid pressure entering the chamber 208' by way of passageway 208' and line I6 under the control of valve 5, will cause the cylinder to move upwardly to the limit of its stroke thereby moving spindle carrier A downwardly into the bore of the workpiece. At the same timeoil is being exhausted through port 2I0, passageway 208 and lines I5 and I! back to the tank I.

Conversely, when it is desired to withdraw the hone from the bore of the workpiece, valve 5 is positioned so that fluid pressure is introduced into the chamber 209 through ports 2I0, passageway 208 and line I5 and simultaneously oil is exhausted from chamber 209' through port 2I0', passageway 208' and line I6.

It is necessary in a machine of this type to provide some means for varying the speed of rotation of the tool as well as the speed of reciprocation thereof. y

In the instant case, the power of reciprocation is controlled by adjusting the spring in valve 3 as is obvious from Figs. 12 and 13. A change in the spring pressure will cause an increase or decrease in the fluid pressure and a corresponding increase or decrease in the power of reciprocation of cylinder D.

The speed of rotation of the tool is varied by means of the mechanism shown in Fig. '7 which comprises'essentially two variable pulleys I I1 and I11 and a shifter lever H5.

Pulley III consists of a stationary part II! joumaled on the reduced end portion of drive shaft H8, and a relatively movable part H which is mounted for rotation on the stub shaft HI and the projecting portion I20 of part In.

Pulley I'I'I' is larger in diameter than pulley ill, but is similar in construction thereto, as can be readily seen from Fig. '7. Pulley I'I'I'is journaled on the driven sleeve I23 and drives the shaft I22 through-the clutch I24. Clutch I24 is of the twin disc type and is engaged and disengaged by the fluid pressure cylinder G.

Speed change lever H is mounted on the easing for lateral swinging movement by means of pivot pin I25 as is apparent from Fig. 7. This is pivotally connected to the movable elements of'pulleys Ill and IT! at I26 and I2! respectively. The extreme lower end of lever II 5 is engaged by the traveling nut I28, which is in turn mounted on the-screw I29. Screw I80 is rotatable by means of handwheei II5.

Thus it can be seen that rotation of the wheel II5 causes the lever IIB to swing about pin I25 in a direction corresponding to the direction of rotation of the wheel. This results in a movement to the left of the movable section H9 of pulley I11 and a complementary movement to the right of section IIS' of pulley I11, or vice versa as the case may be.

The belt I50 is of the well known V-type and rides in the pulleys I11" and I'll. It will be obvious that as the effective diameter of pulley I1! is increased (by moving section II9 toward the left), the belt will move radially outwardly of the pulley and at the same time section II9 of pulley ill will be moved toward the right (under the influence of lever IIB) thus decreascausing the belt I50 to move radially inward.

The pointer I45 indicates on the scale I41 the speed ratio at which the machine is set. The lever F controls the starting and stopping of the honing operation and is positioned on the left side of the machine. Control valves 5, 8 and II are directly associated with the lever F, and the operation thereof may be seen from a reference to Fig. 8.

Lever F is mounted on a rod F which also carries cams H, H and H". Cam H" has a longitudinal groove into which the stem of valve I I enters when the machine is at rest.

Cams H and H control the stems of valves 8 and 5 respectively as is obvious from the drawmgs.

The lever J may operate the stem J of valve 8 through a rack and pinion, as shown in Fig. 8, or a finger and V-lever may be used, as is indicated diagrammatically in Fig. 11. Y

The operation of the device is as follows:

In Fig. 11 the device is shown diagrammatically, the positions of the various parts being shown as they are when the spindle travel is downward.

Before beginning the honing operation the operator first closes the switch (not shown) in the electric power circuit which starts the electric motor I 02.

The hydraulic pump I03, which is directly driven by motor I02, then draws oil from the tank I through line I2 and forces it through line I3 into valve 3, which latter regulates the amount of oil which is allowed to enter the operating system through the main supply line I4. The surplus oil in excess of that used is returned to the supply tank through line '29, and control valves 5 and 6V are supplied with pressure through lines MA and MB respectively. Check valve 5 guards thesystem against excess pressure. Valve II is also supplied with pressure through line 28.

Reference is now made to Figs. 11 and 12. Fig. 12 shows the position of the valves when the cylinder D is traveling upward and the spindle is traveling downward.

To start the honing operation, the operator throws the control lever F into the first intermediate position P (see Fig. 11). This closes valve II thereby shutting off the flow of oil from pilot line 28 to 213 and causes a build up of pressure in the lines by reason of thefact that as soon as oil ceases to flow through line 28, the pressures in chambers X, Y and Z of valve 3 become equal thus allowing the spring toseat piston R.

The operator then by moving the lever F into the second intermediate position P' depresses the piston in valve 5 causing all to flow from MA into line I 6 thereby bringing the liftout cylinder C upward and moving the spindle carrier A downward to the top of the working stroke, and positioning the honing 'tool in the workpiece.

The lever F is then moved to position R. or run positic r lhis causes link J to throw pilot valve 8.;(which receives pressure through line 20 and ports P and I3I of valve 1) thus causing oil to flow from line 2I to lines 26, 26A and 2613. The pressure on line 26B throws clutch cylinder G into run position and pressure on line 26A throws valve '0 into such position that pressure flows from B to linellthus bringing the cylinder D upward and rotating crank E downward to produce the initial working stroke.

Simultaneously the oil on the opposite side of the piston in cylinder D is exhausted through line 24A against the back pressure of foot valve 9 to lines 24 and through the lower exhaust port of valve 6 to lines I10 and "A, through foot valve In which for the moment is in series with foot valve 9, and then through line MD to the storage tank. I

Turning now to Fig. 13, when cylinder D reaches its upper limit of travel, the finger I (see Fig. 11) throws the pilot valve I so that pressure from line 20 is directed through the fullline passage in valve 1 and through line 22 to valve 6. Valve 6 responds by reversing the flow of oil from line 23 to line 24 which in turn causes oil to flow from line B through line 24 and foot valve 9 (which is now operating under free flow) into line 24A leading to the bottom of cylinder D. This causes cylinder D' to travel downwardly and the oil in the top of cylinder D is discharged to the tank I through line 23, the upper exhaust port in valve 6,.line ||C, line I'IA, foot valve In and-line |'|D. Note that in this case, foot valve I0 alone is acting to cushion the shock of reversal of cylinder D.

As cylinder D reaches its lower limit of travel, the finger I30 throws the pilot valve 1 and the above described cycle of operations is repeated until the honing operation is completed or it is desired to check the size of the bore of the workpiece.

Pilot valve '8 is fed from port |3| of pilot valve I through line 2|; thus it will be seen that when pilot valve 1 is thrown as shown in Fig. 13, pilot valve 8 receives no oil flow. When valve 1 is thrown as shown in Fig. 12, pressure oil flows through line 20, ports P and |3| of valve 1, line 2|, ports P and |3| of valve 8 and thus to line 26. It is'therefore obvious that on each downward stroke of cylinder D, the clutch cylinder G receives an impulse of oil through line 263 which tends to keep the clutch in engaged position.

When it is desired to stop the machine (see Figs. 11 and 14), lever F is thrown downward to position P'. This causes valve 8.to reverse its flow and line 26 is connected through the dotted passage in valve 8 to line 21A thereby exhausting oil back to the tank.

When this occurs the next downward movement of the V lever on valve 1 (under the influence of finger I30) throws the ports of valve 1 so that pressure fluid flows from line 20 into line 2| and fluid is exhausted from lines 22 and "C through lines l9 and "B. This precludes further movement of the piston in valve 6 and causes cylinder D to stop. in its downmost position. The pulsating pressure (which occurred during recprocation of the cylinder D) now become constant pressure transmitted through lines 20', 2| and 25 from valve 8 and the clutch is thrown out thereby stopping the rotation of the spindle.

The operator then moves lever F to position P. This permits the piston of valve I to move outwardly and lines A and I! are connected thereby allowing pressure fluid to flow through line I! to cylinder C. This causes liftout cylinder 0 to move downwardly resulting in a rotary motion only of gear sector B (pin III is now stationary due to the cessation of movement of cylinder D) and a consequent addition upward movement of spindle carrier A which withdraws the honing tool from the workpiece.

By moving lever F downwardly to position 8 (or stop position) the valve II is opened there-- fixed, it is unnecessary to change these until it i is desired to hone a workpiece of difierent length.

Valve I8 is a simple needle valve and is merely provided as an adjusting means to limit the time of reversal of valve 6 at the extremities of the stroke. In other words, the length of dwell at the extremities of the working stroke can be regulated by regulating the orifice in the needle valve l8.

Foot valves 9 and I0 function as'back pressure valves to prevent jumping of the hydraulic cylinders during their motion. On the downward stroke of the machine spindle, foot valves 9 and it are in series, but on the upward stroke foot valve I0 only functions. The reason for this is that an effective counterbalancing means may be obtained when very heavy hones are installed on the machine spindle. Ordinarily the mechanical parts of the machine are fairly in balance (due to the downward movement of cylinder D occurring simultaneously with the upward move rhent of the spindle carrier 'A, thus effecting a counterbalance), without the use of valve 9 in the circuit. However, depending upon the weight of the equipment suspended from the spindle, valve 9 may be adjusted to furnish a back pressure or resistance which will counterbalance the same. It will be noted from Fig. 11 that valve In functons as aback pressure valve on both sides of both cylinders C and D because it is injected directly in the return line from both of them.

Valve 6 is provided, at each of its ends, with manually operable means for regulating the rate of fluid flow into and out of said valve from and into lines 22 and 26A. See Figs. 12 and 13.

This means comprises tapered screws 250 and 25 each end of the valve 6, the amount of fluid flowing may be regulated and thus the length of time necessary for reversing the valve may be varied.

In honing closed end bores, the upper'end of the honing tool passes beyond the open end of the bore a fraction of an inch, then reverses its stroke. It is obvious that'the bore receives more abrading at this end than it does at the closed end providing the speed of reversal is the same at both ends of the stroke.

In order to prevent the bore from becoming bell mouthed", the valve 6 may be adjusted so that a longer timeis required to reverse the stroke when the tool is in the bottom of the bore. Thus, the hone remains at the bottom of its stroke for a longer period of time with consequent equalization oi the abrading action.

It is obvious from.the above description that this invention is not limited to a honing machine, but is equally adaptable to a machine for drilling, grinding, lapping or burnishing, and it is not desired to limit the invention except as defined by the claims annexed hereto.

I claim: 1. In a honing machine comprising, in combination, a sectional dumbbell shaped gear seg- By adjusting the size of the openings in ment having gear teeth arranged along the arcuate ends thereof, the teeth of one end engaging a rack gear carried by a longitudinally movable spindle, the teeth carried by the opposite end of said segment engaging a normally stationary rack gear to form a rolling fulcrum for said segment when the same is pivoted by movable means applied at a joint intermediate of its ends to longitudinally move said spindle a predetermined distance, means for holding the intermediate portion of said segment in afixed rotatable position while said normally stationary rack gear is moved to abnormally pivot said segment whereby the spindle is moved beyond said predeter-- mined position.

2. In a honing machine comprising, in combination, a fluid pressure supply, a hydraulically reciprocable cylinder connected to said supply, means operably responsive to the movement of said cylinder for reversing the movement of said fluid to said cylinder, a crank pin associated with the cylinder adapted to be oscillated by the reciprocation thereof, a longitudinally movable spindle, means for transmitting the oscillating movement of said crankpin to longitudinally reciprocate said spindle, and control means adapted upon operation to stop the reciprocation of said cylinder and the reciprocation of said spindle at one end of the stroke.

3. In a machine for honing a cylinder comprising, in combination, a fluid pressure supply, a

hydraulically reciprocable cylinder, means assomanually operable control means cooperating with said first mentioned means adapted upon operation thereof to divert the supply of fluid from said cydinder when said crank arm thereafter reaches one end of said arc.

4. A honing machine comprising in combination, a longitudinally movable spindle, means for rotating the spindle, a rack gear carried by the spindle, a gear segment having arcuate shaped ends and gear teeth arranged along the ends, the teeth at one end of said gear segment engaging said rack gear and the teeth at the opposite end of said segment engaginga normally stationary gear rack, hydraulic operated reciprocating means for swinging said gear segment about said stationary gear rack whereby the spindle is longitudinally reciprocated.

5. In a honing machine comprising, in combination, a longitudinally movable spindle, means for rotating the spindle, a rack gear carried by the spindle, a sectional dumbbell shaped gear segment having teeth arranged along the arcuate ends thereof and movably mounted with the teeth at one end meshing with the teeth of said rackgear and the teeth of the opposite end engaging a normally stationary rack gear, a lever associated with an intermediate portion of said gear segment adapted upon movement thereof to pivot the segment thereby longitudinally moving the spindle by having the stationary rack gear act as the fulcrum for said segment.

6. In -a honing machine comprising, in com-- bination, a fluid pressure supply, a hydraulically reciprocable cylinder, a crank associated with said cylinder adapted to be oscillated by the reciprocation thereof, a floating member engaging a longitudinally movable spindle at one end thereof and a normally stationary hydraulically movable cylinder at its opposite end, means connecting an intermediate portion of said floating member with said oscillating crank to reciprocate said spindle within predetermined limits, manually operable control means associated with said fluid supply and said cylinders movable in one direction through a plurality of predetermined positions, said control means being movable to one position to stop reciprocation of said first mentioned cylinder at one end of the stroke there- 'of, said control means being adapted upon additional movement to another position to direct fluid pressure to said normally stationary cylinder whereby said floating member is pivoted about said intermediate portion and thus move said spindle beyond said predetermined limits.

'7. A honing machine comprising, in combination, a casing, a honing spindle, a rotatable tool associated with the spindle, a gear rack mounted on the casing in a normally stationary position, levermeans connected with the spindle and having teeth thereon in mesh with said gear rack teeth, means for rotating said tool, means for oscillating said spindle about said rack as a center, and means for changing the position of said rack so that the spindle will be oscillated to an abnormal position.

8. In a honing machine, a honing spindle adapted to be reciprocated in the boreof a workpiece, means for reciprocating said spindle within accurately predetermined limits comprising a fluid pressure reciprocating cylinder, a gear rack on said cylinder, a pinion in mesh with said rack, a crank driven by said pinion shaft and an oscillating gear sector member driven by said crank.

9. In a honing machine, in combination, a honing spindle adapted to be reciprocated in the bore of a workpiece, means for reciprocating said spindle within accurately predetermined limits comprising a fluid pressure reciprocating cylinder and a sector member which is adapted to be oscillated about a displacable center by said cylinder, means for reciprocating said spindle beyond said predetermined limits, comprising a second fluid pressure cylinder, said cylinder being operable only when said flrst cylinder is stationary at the bottom of its stroke.

10. In a honing machine, a honing spindle, having teeth thereon, a normally stationary liftout cylinder, a gear sector member adapted to pivot on the liftout cylinder and having gear teeth which mesh with the teeth on the spindle, and means for oscillating the gear sector member.

11. In a honing machine, a honing spindle having rack teeth thereon, a normally stationary liftout cylinder having rack teeth thereon, a gear sector member having oppositely disposed sets of teeth adapted to mesh with the spindle teeth and the liftout cylinder teeth respectively, means for oscillating the gear sector member about the liftout cylinder whereby the spindle is reciprocated.

12. In a honing machine, a spindle provided with a honing tool which is adapted to be rotated and reciprocated simultaneously, means for rotating the tool, means for reciprocating the tool, said last named means comprising a reciprocating cylinder, a normally stationary cylin" and a lever pivoted on the last said cylinder a adapted to be reciprocated by the reciprocating cylinder.

13. In a honing machine, in combination, a honing spindle adapted to be reciprocated within the bore of a workpiece, a rotatable honing tool mounted in said spindle, means for reciprocating said spindle, means for rotating said tool, sepa-, rate means for withdrawing said spindle and tool from the bore of the workpiece, a control lever adapted to be moved to a plurality of positions, one of which causesthe stopping of the reciprocating and rotating means and another 01' which causes operation 01' the withdrawing means.

, 14. A honing machine having a spindle member adapted to oscillate in a bore of a workpiece, a normally stationary liftout member, means for oscillating the spindle member about a center located on the liftout member and means associated with the liftout memberior displacing said center for the purpose of withdrawing the spindle from the workpiece.

15. In fluid pressure actuated mechanism, in combination, a fluid pressure reciprocating cylinder, a source of fluid pressure, a fluid supply tank,

pressure lines connecting said cylinder with said source, exhaust lines connecting said cylinder with said tank, a pair of back pressure valves connected in the exhaust lines in such relationship that one of the said valves is in series with the cylinder on the downstroke thereof and both of tool and the mechanical means to rotate the tool.

JOHN E. G. KLIINE. 

